1. Field of the Invention
The invention relates to a prosthetic knee joint with four pivot pins for connecting four joint members, said joint members each being supported at each of their ends in a pivot pin, wherein two opposite, transversely extending joint members are connectable at one end to a prosthetic stem and at the other end to a prosthetic foot, wherein the other two joint members as longitudinal joint members, in both the standing position and the bending position, are adapted to pivot essentially out of an angled position approximate to the parallel position into a relatively more greatly inclined position with respect to each other.
2. Description of Background Art
Such a prosthetic joint is published in DE 40 04 988 A1. In order to improve the standing stability of said prosthetic knee joint on the one hand and to facilitate bending of the knee on the other hand, one pivot pin, disposed in the joint member connected to the prosthetic foot, is supported in an oblong hole and is lockable therein by tightening a screw, whereby, in the case of an effectively increased distance between the pivot pins of said joint member, bending of the prosthesis is facilitated and, in the case of a shortening of the distance between the respective pivot pins through corresponding displacement in the oblong hole, the standing stability is increased. It has been demonstrated that, on the one hand, the permanent secure locking of the respective pivot pin, displaceable in the oblong hole, cannot always be guaranteed and that, on the other hand, the pivot pin in the oblong hole is unable, because of its basically exclusively linear contact with the inside surface of the oblong hole, to guarantee the required stability of the respective position of the pivot pin.